The present invention relates to the vacuum pump arts. It finds particular application in a vacuum pump with a shaft bearing. The vacuum pump supports itself via its bearing outer ring and includes a damping means in its housing.
Vacuum pumps which have rapidly rotating rotors tend to vibrate. To reduce the vibration of the vacuum pumps, damping means are provided through shaft bearings. The shaft bearing is also used to support the vacuum pump in its housing. Radial stiffness of the damping means is also of importance in addition to the damping itself.
Vacuum pumps which operate at high speeds and include damping means are well known. For example, two known vacuum pumps with damping means are disclosed in DE-A-37 822 and EU-A 196-342. Pumps of this type are frequently employed in measuring instruments (e.g., electronic microscopes), where vibrations are highly troublesome. With these pumps, the bearings of the rotor shafts support themselves in the pump housing either directly or indirectly through spindle bearings and elastomer rings or elastomer ring systems. These damping means allow general damping behavior through the diameters and material of the rings. Specific damping, however, involves a certain radial stiffness.
The use of O-rings for damping has disadvantages in that O-rings have a shorter life expectancy than bearings and are less homogeneous and are more expensive to manufacture than bearing support rings.